London: Israel is preparing for a ground attack on Iran before Christmas, after conducting commando dry runs in the Iraq desert, a media report said.

Top military officials in Tel Aviv believe they have until the end of the year to strike at Iran's nuclear programme.

The main target would be a heavily fortified uranium enrichment plant at Fordo, near the holy city of Qom.

Israeli leaders have reportedly made it clear they are ready to launch military action alone - if the US does not help.

Late October or early November have been identified by intelligence analysts as a likely time because of the US elections Nov 6.

"We know the Israelis have been active in the Iraq desert, it would appear preparing forward bases for a ground assault. Bombing Iranian nuclear installations will most likely be a part of their plan, but the only way to confirm they have destroyed what they need to is to put boots on the ground," an unnamed British official was quoted as saying.

"It is a very big concern. Iran would have to retaliate, putting the region into an extremely dangerous situation," he said.

An "anonymous senior Israeli politician" -- believed to be defence minister Ehud Barak -- made it clear to The Sun that Israel had already decided to act alone.

"We can't wait to find out one morning that we relied on the Americans but were fooled because the Americans didn't act. Israel is strong and Israel is responsible, and will do what it has to do," the minister said.